After Mandela was free (自由的) in 1990, he chose to shake hands with the people ________ wanted to kill him.

Do you want to be healthy? ______. Smiling can help you stay healthy.

It took him ____ to find the key to the drawer.

As we all know, many Chinese words have come into English, ______ typhoon, tofu and kung fu.

When has the country been open to internationaltrade?—_____1978 , Isuppose